Introducing commulative acks
Improved cummack structure
Re-worked cummacks to introduce distant ranges
Added backwards compatibility by means of negType
Actual negType definition
Updated unit tests to a new ack format
Yet another unit-test update
Merge remote-tracking branch 'quadrocube/transport-layer-modifications' into cumulative-acks

Conflicts:
	src/freenet/node/FNPPacketMangler.java
Catch more specific exception.
Check packet size when adding acks.
Add more unit tests.
Simplify code slightly.
Check length, this should pick up some subtle bugs.
Check a single range.
Remove bogus Math.abs()
Fix bogus assertion I introduced in 5456e6401726900052b9e0f8a219798862fdaf86
Merge branch 'cumulative-acks' into next